Pressure-gage



3 Sheets-Sheet 1.

O. A; G. WINTHlEiR.v

' PRESSURE GAGE.

Patented Jan. 5 1892.

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9M -8 mas nmm (No Model.) 7 '3 Sheets-Sheet 2.- G. A. G. WINTHER. I

'PREssURE GAGE. I No. 466,547. Patented Jan. 5, 1892.

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o. A. G WINTHER.

PRESSUREUGAGE- I No. 466,547. I Patented J n. 5, 1892.

I WITNESSES- UNITED STATES PATENT OFFICE.

CHARLES A. G. WINTI-IER, OF SOMERVILLE, ASSIGNOR OF ONE-HALF TO THE STARBRASS MANUFACTURING COMPANY, OF BOSTON, MASSACHUSETTS.

PRESSURE-GAGE.

SPECIFICATION forming part of Letters Patent No. 466,547, dated January5,1892.

Application filed June 22, 1891.

To all whom it may concern: I

Be it known that I, CHARLES A. G. WVINTHER, of Somerville, in thecountyof Middlesex and State of Massachusetts, a citizen of the UnitedStates of America, have invented certain new and useful Improvements onthe Steam-Gage, of which the following, reference being had to theaccompanying drawings, forming part of the specification, is a full,accurate, and complete specification sufficient to enable others skilledin the art to make and use my improvement.

In the drawings, Figure l is a front elevation of a gage containingthese improvements. Fig. 2 is a back elevation'of a gage containng theseimprovements Fig. 3 is a side elevation of a gage containing theseimprovements. Fig. 4 is a front elevation of the working parts of thegage, part of the case being broken away. In this drawing the positionof the hand does not accurately correspond to the position of the rackand steam springs; but it was thought desirable to show the hand andhair-spring of the gage in this figure, and a position more nearlycorresponding with the position of the rack would probably have partially concealed the rack, which it was desirable to show. Fig. 5 is anelevation of some of the working parts of the gage, showing, also, otherparts in section and some parts imperfectly. Fig. 6 is a detail drawingof the connection between the spring-actuated lever and thespring-actuated link. Fig. 7 is a transverse section of the part shownin Fig. 6 upon the line X X. Figs. 8 and 9 are transverse sections ofthe steam-spring.

Like letters indicate like parts in all the figures. I

In the drawings, Fig. 3, Ais thebezel, which contains the glass front ofthe gage and which is screwed upon the body of the gage G. This body iscontinued into a vertical flange, as shown in Fig. 3, which vertical.flange is scalloped, as shown in that figure, havingdownwardly-projecting portions 13, as shown in Figs. 3 and 2. The objectof providing the body of the gage with a scalloped flange sub-'stantially parallel to the pivotal axis of the gage movement is for thepurpose of preventing contact between the metallic back of the gage-caseand the hot boiler, against which it- I Serial No. 397,064. (No model.)

is customary to erect a locomotive-gage. By thus setting the gage-caseoff from the boiler by detached feet, as they may be called, an

airspace is provided between the boiler-sum 5 5 .face and the case ofthe gage, which air-space communicates freely with the surrounding air,

and hence is kept at a temperature not much in excess of that of thegeneral atmosphere of the locomotive-cab or engine-room, and thisarrangement for spacing the back of the gagecase off from the boiler andproviding the airspace whichintervenes between the back of the gage andthe boiler with means of communication with the surrounding atmosphereconstitutes the first part of my improvements.

The second part of my improvements consists in an arrangement foradjusting the leverage of the lever which communicates the motion of theends of the steam-spring to the some of which are shown in the presentapplication. Y

The Lane gage is a double spring-gage in which the two branches of theBourdon tube are symmetrically disposed on either side of an imaginaryvertical and lay hold directly or indirectly of a depending lever notfastened to the case of the gage, which lever communicates motion to arack which engages with the index-pinion of the movement.

In the drawings, Fig. 4, E are the two branches of the Bourdon tube.Each of these branches is closed at its free end by a tip e,

and the two branches of the tube are fastened to the hollow boss D, theinterior of which communicates with the source of steam-supply. Upon theright-hand spring is pivoted at its free end the lever F, the upper endof which is shaped as shown in the drawings, 5

Fig. 5. It has a pivot-hole f in line with the pivot which connects thesaid lever with the tip a on the right-hand spring. This lever also hasan ear f projecting diagonally upward and furnished with a hole which isthreadedzroo for the insertion of the clamping-screw. The lower end ofthe lever F is also provided with Certain improvements 7 5 upon it havebeen introduced of recent years,

a hole for the insertion of a screw which connects the lever F with therack G.

O is an eccentric. It is slotted on one side, as shown in Fig. 7, forthe insertion of the link N, and a transverse hole 19, threaded for theinsertion of a pivot-screw, is made to traverse the slot and serves as apivot for the link N. This eccentric O is furnished with a projectionaway from its center, which is inserted into the hole f of the lever F,and by turning the eccentric 0 around this projection the distancebetween the pivotal connection of the link N with the lever F and thepivotal connection of the same lever with the right-hand spring E can beregulated; but in order when this distance has been properly ascertainedto fix it correctly, the eccentric O has projecting from it a slottedsegment 0 the slot in which coincides with the screwhole in the ear f ofthe lever F. A slot is shown in the head of the eccentric for theinsertion of a screw-driver to turn the eccentric on its pivot. Aclamping-screw 7, shown in the drawings, Figs. 4 and 7, serves to clamptogether the eccentric O and lever at any position of the pivot 19 whichmay be desirable.

A third part of my invention relates to means for keeping the teeth ofthe rack G in contact with the pinion 70. As the lower end of the leverF runs to and froin an are which varies but little from a circular aredescribed around a center lying somewhat to the left of the body of thelever F between its two pivotal points of connection to or toward thespring ends, the angle of the rack G with the vertical of the gage-easewill vary somewhat, and it has always been necessary to provide somemeans for keeping the teeth of the rack and of the pinion in engagement,and it has been found that the pressure of the point of a setscrew, orofthe periphery of a wheel, or of a transverse rod is nota desirable wayof keeping these teeth in engagement. The use of a hair-spring, as shownin Fig. 4 at S, will prevent backlash of the teeth, but will not preventthem from jumping up and down. I have found that by making a conical orconoidal recess in the bottom of the set-screw L and inserting in thehollow of this recess a small steel ball, or ball of other hard metal,better results are reached than by the other ways I have mentioned whichwere formerly employed. This ball gives a rolling friction substantiallyas well as a wheel, and, having no fixed axis of revolution, is notliable to some of the objections of a wheel. If the ball fitted therecess and bore upon it over half its circumference it probably wouldhave too much friction to be of much service; but in the conical orcolloidal recess it bears only at a portion of its circumference, andthis portion of its circumference forms a circle less than a greatcircle, and thus apparently causes an imaginary axis of revolution to beestablished, not through the center of the ball, but at some point near,if not coincident with, a line parallel to the horizontal axis of theball and near in position to the circle of contact between the internalcavity of the set-screw and the said ball.

In the drawings, Fig. 5, L is the set-screw, which is driven into aframe II, the flange of which is attached to the back of the gage.indicates the recess in the point of the setscrew, and m the hard-metalball resting on the rack G. K is the pinion of the indicating-hand.

he fourth improvement which I have devised relates to the steam-spring.This, as 18 well known, usually consists of a hollow flattened tube bentinto an arc of a circle. The admission of pressure into this tube causesit to expand, and in expanding to stralghten, and, as the tube is fastat its butt to the boss D, the straightening of the tube gives an upwardand outward movement on an evolute curve to the free end of the springto which the tips a are attached. The movement of the free end of agage-tube is usually in actual practice very limited, and this movementis enhanced by leverages to form the indications of comparative pressureby the springs are usually made of brass or composition, and as themetal of winch these tubes are usually formed is ametal WlllCllhammerhardens and receives a spring-temper from work bestowed upon itand which anneals under heat, much trouble arises from the weakening ofsprings or from the setting of springs when they are first put in use.These springs, as I have said, are of comparatively ellipticalcross-section, and the curvature into which they are put in bending themfor use in the gage is a curvature which disturbs the horizontalrelation of planes through which the shorter axis of the ellipse runs.

The parts of the Bourdon tube which are in spring-tension are the longersides of the ellipse, and the spring of the tube is due to the tensionand compression of the metal which lies in these longer sides of theellipse. In order to make the spring somewhat less susceptible tosetting, I provide one or more longitudinal ribs on one or both of thelonger sides of its elliptic cross-section. These ribs are shown inFigs. 8 and 9 at r. I do not, however, confine myself to two ribs, orinsist that there should be more than one. I do not ,confine myself toribs upon the inner side of the curvature of the spring or upon theconvex side of the curvature of the spring; but I may bend the spring sothat these ribs shall movement of a hand upon a dial. These be on theconvex or on the concave side of the finished spring, or on both sidesof the finished spring.

Having thus described my invention, what I claim as my improvements, anddesire to secure by Letters Patent, is-

1. The combination of the lever F, provided with the pivot-hole f andear f, with the link N and eccentric 0, provided with the slottedsegment-flange o and clamping-screw q, substantially as and for thepurpose described.

2. The combination of the pinion K, rack I 3. In combination with thesteam-spring of a Bourdon gage of elliptical cross-section, the ribs 0",formed upon one or both of the long sides of said spring and runninglongitudinally of said spring, substantially as and for the purposedescribed.

CHARLES A. G. VV'INTHER.

Witnesses:

J. M. DOLAN, M. MOFAGUE.

